In preparation for installing this header as a common public header for use by other projects, rename it. --- common/protocol/Makefile.am | 10 +++++----- common/protocol/{protocol.h => nbd-protocol.h} | 6 +++--- common/protocol/protostrings.sed | 6 +++--- plugins/nbd/nbd-standalone.c | 2 +- server/protocol-handshake-newstyle.c | 2 +- server/protocol-handshake-oldstyle.c | 2 +- server/protocol-handshake.c | 2 +- server/protocol.c | 2 +- tests/test-layers.c | 2 +- 9 files changed, 17 insertions(+), 17 deletions(-) diff --git a/common/protocol/Makefile.am b/common/protocol/Makefile.am index 99df43b..996be26 100644 --- a/common/protocol/Makefile.am +++ b/common/protocol/Makefile.am @@ -32,7 +32,7 @@ include $(top_srcdir)/common-rules.mk EXTRA_DIST = \ - protocol.h \ + nbd-protocol.h \ protostrings.c \ protostrings.sed \ $(NULL) @@ -41,16 +41,16 @@ noinst_LTLIBRARIES = libprotocol.la libprotocol_la_SOURCES = \ protostrings.c \ - protocol.h \ + nbd-protocol.h \ $(NULL) libprotocol_la_CFLAGS = $(WARNINGS_CFLAGS) -# protostrings.c is generated from the protocol.h header file where it -# is used to map NBD protocol flags to strings. +# protostrings.c is generated from the nbd-protocol.h header file +# where it is used to map NBD protocol flags to strings. BUILT_SOURCES = protostrings.c CLEANFILES += protostrings.c -protostrings.c: protocol.h protostrings.sed Makefile +protostrings.c: nbd-protocol.h protostrings.sed Makefile rm -f $@ $@-t $(SED) -n -f $(srcdir)/protostrings.sed < $< > $@-t mv $@-t $@ diff --git a/common/protocol/protocol.h b/common/protocol/nbd-protocol.h similarity index 99% rename from common/protocol/protocol.h rename to common/protocol/nbd-protocol.h index bf54839..da2e0d0 100644 --- a/common/protocol/protocol.h +++ b/common/protocol/nbd-protocol.h @@ -30,8 +30,8 @@ * SUCH DAMAGE. */ -#ifndef NBDKIT_PROTOCOL_H -#define NBDKIT_PROTOCOL_H +#ifndef NBD_PROTOCOL_H +#define NBD_PROTOCOL_H #include <stdint.h> @@ -244,4 +244,4 @@ extern const char *name_of_nbd_error (int); #define NBD_ENOTSUP 95 #define NBD_ESHUTDOWN 108 -#endif /* NBDKIT_PROTOCOL_H */ +#endif /* NBD_PROTOCOL_H */ diff --git a/common/protocol/protostrings.sed b/common/protocol/protostrings.sed index 1731c6b..cb1a76e 100644 --- a/common/protocol/protostrings.sed +++ b/common/protocol/protostrings.sed @@ -29,12 +29,12 @@ # OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF # SUCH DAMAGE. -# Generate the protostrings.c file from protocol.h. +# Generate the protostrings.c file from nbd-protocol.h. # Prologue. 1i\ -/* Generated from protocol.h by protostrings.sed. */\ -\#include "protocol.h"\ +/* Generated from nbd-protocol.h by protostrings.sed. */\ +\#include "nbd-protocol.h"\ # Match the precise sections of the source file. diff --git a/plugins/nbd/nbd-standalone.c b/plugins/nbd/nbd-standalone.c index 0fabbfe..a6779a4 100644 --- a/plugins/nbd/nbd-standalone.c +++ b/plugins/nbd/nbd-standalone.c @@ -53,7 +53,7 @@ #define NBDKIT_API_VERSION 2 #include <nbdkit-plugin.h> -#include "protocol.h" +#include "nbd-protocol.h" #include "byte-swapping.h" #include "cleanup.h" diff --git a/server/protocol-handshake-newstyle.c b/server/protocol-handshake-newstyle.c index 38978c6..866360b 100644 --- a/server/protocol-handshake-newstyle.c +++ b/server/protocol-handshake-newstyle.c @@ -41,7 +41,7 @@ #include "internal.h" #include "byte-swapping.h" -#include "protocol.h" +#include "nbd-protocol.h" /* Maximum number of client options we allow before giving up. */ #define MAX_NR_OPTIONS 32 diff --git a/server/protocol-handshake-oldstyle.c b/server/protocol-handshake-oldstyle.c index f5425d3..87cb265 100644 --- a/server/protocol-handshake-oldstyle.c +++ b/server/protocol-handshake-oldstyle.c @@ -41,7 +41,7 @@ #include "internal.h" #include "byte-swapping.h" -#include "protocol.h" +#include "nbd-protocol.h" int protocol_handshake_oldstyle (struct connection *conn) diff --git a/server/protocol-handshake.c b/server/protocol-handshake.c index a0d7dc2..2c2f35e 100644 --- a/server/protocol-handshake.c +++ b/server/protocol-handshake.c @@ -41,7 +41,7 @@ #include "internal.h" #include "byte-swapping.h" -#include "protocol.h" +#include "nbd-protocol.h" int protocol_handshake (struct connection *conn) diff --git a/server/protocol.c b/server/protocol.c index e65a078..498db1d 100644 --- a/server/protocol.c +++ b/server/protocol.c @@ -45,7 +45,7 @@ #include "internal.h" #include "byte-swapping.h" #include "minmax.h" -#include "protocol.h" +#include "nbd-protocol.h" static bool validate_request (struct connection *conn, diff --git a/tests/test-layers.c b/tests/test-layers.c index 9b595c4..1097f15 100644 --- a/tests/test-layers.c +++ b/tests/test-layers.c @@ -61,7 +61,7 @@ #include "byte-swapping.h" #include "cleanup.h" #include "exit-with-parent.h" -#include "protocol.h" +#include "nbd-protocol.h" /* Declare program_name. */ #if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME == 1 -- 2.23.0

Use a simple bash script to generate the protostrings.c functions. Remove the extern decls from the nbd-protocol.h file which were used previously in the generation of this file. They have been moved to a new internal header called "protostrings.h". --- common/protocol/Makefile.am | 8 ++- ...tostrings.sed => generate-protostrings.sh} | 56 +++++++++++-------- common/protocol/nbd-protocol.h | 10 ---- common/protocol/protostrings.h | 51 +++++++++++++++++ plugins/nbd/nbd-standalone.c | 1 + server/protocol-handshake-newstyle.c | 1 + server/protocol.c | 1 + 7 files changed, 91 insertions(+), 37 deletions(-) diff --git a/common/protocol/Makefile.am b/common/protocol/Makefile.am index 996be26..74c288a 100644 --- a/common/protocol/Makefile.am +++ b/common/protocol/Makefile.am @@ -34,13 +34,14 @@ include $(top_srcdir)/common-rules.mk EXTRA_DIST = \ nbd-protocol.h \ protostrings.c \ - protostrings.sed \ + generate-protostrings.sh \ $(NULL) noinst_LTLIBRARIES = libprotocol.la libprotocol_la_SOURCES = \ protostrings.c \ + protostrings.h \ nbd-protocol.h \ $(NULL) libprotocol_la_CFLAGS = $(WARNINGS_CFLAGS) @@ -50,8 +51,9 @@ libprotocol_la_CFLAGS = $(WARNINGS_CFLAGS) BUILT_SOURCES = protostrings.c CLEANFILES += protostrings.c -protostrings.c: nbd-protocol.h protostrings.sed Makefile + +protostrings.c: nbd-protocol.h generate-protostrings.sh Makefile rm -f $@ $@-t - $(SED) -n -f $(srcdir)/protostrings.sed < $< > $@-t + SED=$(SED) $(srcdir)/generate-protostrings.sh > $@-t mv $@-t $@ chmod 0444 $@ diff --git a/common/protocol/protostrings.sed b/common/protocol/generate-protostrings.sh old mode 100644 new mode 100755 similarity index 61% rename from common/protocol/protostrings.sed rename to common/protocol/generate-protostrings.sh index cb1a76e..d3f5d18 --- a/common/protocol/protostrings.sed +++ b/common/protocol/generate-protostrings.sh @@ -1,5 +1,6 @@ +#!/usr/bin/env bash # nbdkit -# Copyright (C) 2018 Red Hat Inc. +# Copyright (C) 2018-2019 Red Hat Inc. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions are @@ -29,30 +30,37 @@ # OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF # SUCH DAMAGE. -# Generate the protostrings.c file from nbd-protocol.h. +# The header. +cat <<'EOF' +/* Generated from nbd-protocol.h by generate-protostrings.sh. */ -# Prologue. -1i\ -/* Generated from nbd-protocol.h by protostrings.sed. */\ -\#include "nbd-protocol.h"\ +#include "nbd-protocol.h" +EOF -# Match the precise sections of the source file. -/^extern const char \*name_of_/,/^$/ { +declare -A functions=( + [global_flag]=NBD_FLAG_FIXED_NEWSTYLE + [flag]=NBD_FLAG_HAS_FLAGS + [opt]=NBD_OPT_EXPORT_NAME + [rep]=NBD_REP_ACK + [info]=NBD_INFO_EXPORT + [reply]=NBD_REPLY_FLAG_DONE + [reply_type]=NBD_REPLY_TYPE_NONE + [cmd]=NBD_CMD_READ + [cmd_flag]=NBD_CMD_FLAG_FUA + [error]=NBD_SUCCESS +) - # Convert extern function prototype into a definition. - s/extern \(const char \*name_of_.*\) (int);/\1 (int fl) {\ - switch (fl) {/; - - # Convert #define lines into cases. - s/^#define \([_A-Z]*\).*/ case \1: return "\1\";/; - - # Append closing brace. - s/^$/ default: return "unknown";\ - }\ -}/; - - # Print pattern buffer. - p; - -} +# Generate each 'const char *name_of_nbd_<fn>' +for fn in "${!functions[@]}"; do + echo 'extern const char *' + echo "name_of_nbd_$fn (int fl)" + echo '{' + echo ' switch (fl) {' + $SED -n "/^#define ${functions[$fn]}/,/^$/p" nbd-protocol.h | + $SED 's/^#define \([_A-Z]*\).*/ case \1:\n return "\1\";/' + echo ' default: return "unknown";' + echo ' }' + echo '}' + echo +done diff --git a/common/protocol/nbd-protocol.h b/common/protocol/nbd-protocol.h index da2e0d0..60d35d0 100644 --- a/common/protocol/nbd-protocol.h +++ b/common/protocol/nbd-protocol.h @@ -80,12 +80,10 @@ struct fixed_new_option_reply { #define NBD_REP_MAGIC UINT64_C(0x3e889045565a9) /* Global flags. */ -extern const char *name_of_nbd_global_flag (int); #define NBD_FLAG_FIXED_NEWSTYLE 1 #define NBD_FLAG_NO_ZEROES 2 /* Per-export flags. */ -extern const char *name_of_nbd_flag (int); #define NBD_FLAG_HAS_FLAGS (1 << 0) #define NBD_FLAG_READ_ONLY (1 << 1) #define NBD_FLAG_SEND_FLUSH (1 << 2) @@ -99,7 +97,6 @@ extern const char *name_of_nbd_flag (int); #define NBD_FLAG_SEND_FAST_ZERO (1 << 11) /* NBD options (new style handshake only). */ -extern const char *name_of_nbd_opt (int); #define NBD_OPT_EXPORT_NAME 1 #define NBD_OPT_ABORT 2 #define NBD_OPT_LIST 3 @@ -113,7 +110,6 @@ extern const char *name_of_nbd_opt (int); #define NBD_REP_ERR(val) (0x80000000 | (val)) #define NBD_REP_IS_ERR(val) (!!((val) & 0x80000000)) -extern const char *name_of_nbd_rep (int); #define NBD_REP_ACK 1 #define NBD_REP_SERVER 2 #define NBD_REP_INFO 3 @@ -124,7 +120,6 @@ extern const char *name_of_nbd_rep (int); #define NBD_REP_ERR_PLATFORM NBD_REP_ERR (4) #define NBD_REP_ERR_TLS_REQD NBD_REP_ERR (5) -extern const char *name_of_nbd_info (int); #define NBD_INFO_EXPORT 0 /* NBD_INFO_EXPORT reply (follows fixed_new_option_reply). */ @@ -197,14 +192,12 @@ struct structured_reply_error { #define NBD_STRUCTURED_REPLY_MAGIC 0x668e33ef /* Structured reply flags. */ -extern const char *name_of_nbd_reply_flag (int); #define NBD_REPLY_FLAG_DONE (1<<0) #define NBD_REPLY_TYPE_ERR(val) ((1<<15) | (val)) #define NBD_REPLY_TYPE_IS_ERR(val) (!!((val) & (1<<15))) /* Structured reply types. */ -extern const char *name_of_nbd_reply_type (int); #define NBD_REPLY_TYPE_NONE 0 #define NBD_REPLY_TYPE_OFFSET_DATA 1 #define NBD_REPLY_TYPE_OFFSET_HOLE 2 @@ -213,7 +206,6 @@ extern const char *name_of_nbd_reply_type (int); #define NBD_REPLY_TYPE_ERROR_OFFSET NBD_REPLY_TYPE_ERR (2) /* NBD commands. */ -extern const char *name_of_nbd_cmd (int); #define NBD_CMD_READ 0 #define NBD_CMD_WRITE 1 #define NBD_CMD_DISC 2 /* Disconnect. */ @@ -223,7 +215,6 @@ extern const char *name_of_nbd_cmd (int); #define NBD_CMD_WRITE_ZEROES 6 #define NBD_CMD_BLOCK_STATUS 7 -extern const char *name_of_nbd_cmd_flag (int); #define NBD_CMD_FLAG_FUA (1<<0) #define NBD_CMD_FLAG_NO_HOLE (1<<1) #define NBD_CMD_FLAG_DF (1<<2) @@ -233,7 +224,6 @@ extern const char *name_of_nbd_cmd_flag (int); /* Error codes (previously errno). * See http://git.qemu.org/?p=qemu.git;a=commitdiff;h=ca4414804114fd0095b317785b... */ -extern const char *name_of_nbd_error (int); #define NBD_SUCCESS 0 #define NBD_EPERM 1 #define NBD_EIO 5 diff --git a/common/protocol/protostrings.h b/common/protocol/protostrings.h new file mode 100644 index 0000000..8029652 --- /dev/null +++ b/common/protocol/protostrings.h @@ -0,0 +1,51 @@ +/* nbdkit + * Copyright (C) 2018-2019 Red Hat Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * * Neither the name of Red Hat nor the names of its contributors may be + * used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef NBDKIT_PROTOSTRINGS_H +#define NBDKIT_PROTOSTRINGS_H + +/* The corresponding functions are generated by + * generate-protostrings.sh from the nbd-protocol.h header file. + */ + +extern const char *name_of_nbd_global_flag (int); +extern const char *name_of_nbd_flag (int); +extern const char *name_of_nbd_opt (int); +extern const char *name_of_nbd_rep (int); +extern const char *name_of_nbd_info (int); +extern const char *name_of_nbd_reply_flag (int); +extern const char *name_of_nbd_reply_type (int); +extern const char *name_of_nbd_cmd (int); +extern const char *name_of_nbd_cmd_flag (int); +extern const char *name_of_nbd_error (int); + +#endif /* NBDKIT_PROTOSTRINGS_H */ diff --git a/plugins/nbd/nbd-standalone.c b/plugins/nbd/nbd-standalone.c index a6779a4..1789e39 100644 --- a/plugins/nbd/nbd-standalone.c +++ b/plugins/nbd/nbd-standalone.c @@ -54,6 +54,7 @@ #include <nbdkit-plugin.h> #include "nbd-protocol.h" +#include "protostrings.h" #include "byte-swapping.h" #include "cleanup.h" diff --git a/server/protocol-handshake-newstyle.c b/server/protocol-handshake-newstyle.c index 866360b..104796a 100644 --- a/server/protocol-handshake-newstyle.c +++ b/server/protocol-handshake-newstyle.c @@ -42,6 +42,7 @@ #include "internal.h" #include "byte-swapping.h" #include "nbd-protocol.h" +#include "protostrings.h" /* Maximum number of client options we allow before giving up. */ #define MAX_NR_OPTIONS 32 diff --git a/server/protocol.c b/server/protocol.c index 498db1d..8df5ed5 100644 --- a/server/protocol.c +++ b/server/protocol.c @@ -46,6 +46,7 @@ #include "byte-swapping.h" #include "minmax.h" #include "nbd-protocol.h" +#include "protostrings.h" static bool validate_request (struct connection *conn, -- 2.23.0

Diff against libnbd’s copy of this file, and change this one until it matches. --- common/protocol/nbd-protocol.h | 76 +++++++++++++++++----------- server/protocol-handshake-newstyle.c | 26 +++++----- server/protocol-handshake-oldstyle.c | 4 +- server/protocol.c | 25 ++++----- tests/test-layers.c | 14 ++--- 5 files changed, 81 insertions(+), 64 deletions(-) diff --git a/common/protocol/nbd-protocol.h b/common/protocol/nbd-protocol.h index 60d35d0..724ffb6 100644 --- a/common/protocol/nbd-protocol.h +++ b/common/protocol/nbd-protocol.h @@ -40,37 +40,46 @@ * these structures. */ +#define NBD_MAX_STRING 4096 /* Maximum length of a string field */ + /* Old-style handshake. */ -struct old_handshake { +struct nbd_old_handshake { char nbdmagic[8]; /* "NBDMAGIC" */ - uint64_t version; /* OLD_VERSION */ + uint64_t version; /* NBD_OLD_VERSION */ uint64_t exportsize; uint16_t gflags; /* global flags */ uint16_t eflags; /* per-export flags */ char zeroes[124]; /* must be sent as zero bytes */ } __attribute__((packed)); -#define OLD_VERSION UINT64_C(0x420281861253) +#define NBD_OLD_VERSION UINT64_C(0x420281861253) /* New-style handshake. */ -struct new_handshake { +struct nbd_new_handshake { char nbdmagic[8]; /* "NBDMAGIC" */ - uint64_t version; /* NEW_VERSION */ + uint64_t version; /* NBD_NEW_VERSION */ uint16_t gflags; /* global flags */ } __attribute__((packed)); -#define NEW_VERSION UINT64_C(0x49484156454F5054) +#define NBD_NEW_VERSION UINT64_C(0x49484156454F5054) /* New-style handshake option (sent by the client to us). */ -struct new_option { +struct nbd_new_option { uint64_t version; /* NEW_VERSION */ uint32_t option; /* NBD_OPT_* */ uint32_t optlen; /* option data length */ /* option data follows */ } __attribute__((packed)); +/* Newstyle handshake OPT_EXPORT_NAME reply message. */ +struct nbd_export_name_option_reply { + uint64_t exportsize; /* size of export */ + uint16_t eflags; /* per-export flags */ + char zeroes[124]; /* optional zeroes */ +} __attribute__((packed));; + /* Fixed newstyle handshake reply message. */ -struct fixed_new_option_reply { +struct nbd_fixed_new_option_reply { uint64_t magic; /* NBD_REP_MAGIC */ uint32_t option; /* option we are replying to */ uint32_t reply; /* NBD_REP_* */ @@ -110,33 +119,37 @@ struct fixed_new_option_reply { #define NBD_REP_ERR(val) (0x80000000 | (val)) #define NBD_REP_IS_ERR(val) (!!((val) & 0x80000000)) -#define NBD_REP_ACK 1 -#define NBD_REP_SERVER 2 -#define NBD_REP_INFO 3 -#define NBD_REP_META_CONTEXT 4 -#define NBD_REP_ERR_UNSUP NBD_REP_ERR (1) -#define NBD_REP_ERR_POLICY NBD_REP_ERR (2) -#define NBD_REP_ERR_INVALID NBD_REP_ERR (3) -#define NBD_REP_ERR_PLATFORM NBD_REP_ERR (4) -#define NBD_REP_ERR_TLS_REQD NBD_REP_ERR (5) +#define NBD_REP_ACK 1 +#define NBD_REP_SERVER 2 +#define NBD_REP_INFO 3 +#define NBD_REP_META_CONTEXT 4 +#define NBD_REP_ERR_UNSUP NBD_REP_ERR (1) +#define NBD_REP_ERR_POLICY NBD_REP_ERR (2) +#define NBD_REP_ERR_INVALID NBD_REP_ERR (3) +#define NBD_REP_ERR_PLATFORM NBD_REP_ERR (4) +#define NBD_REP_ERR_TLS_REQD NBD_REP_ERR (5) +#define NBD_REP_ERR_UNKNOWN NBD_REP_ERR (6) +#define NBD_REP_ERR_SHUTDOWN NBD_REP_ERR (7) +#define NBD_REP_ERR_BLOCK_SIZE_REQD NBD_REP_ERR (8) +#define NBD_REP_ERR_TOO_BIG NBD_REP_ERR (9) #define NBD_INFO_EXPORT 0 /* NBD_INFO_EXPORT reply (follows fixed_new_option_reply). */ -struct fixed_new_option_reply_info_export { +struct nbd_fixed_new_option_reply_info_export { uint16_t info; /* NBD_INFO_EXPORT */ uint64_t exportsize; /* size of export */ uint16_t eflags; /* per-export flags */ } __attribute__((packed)); /* NBD_REP_META_CONTEXT reply (follows fixed_new_option_reply). */ -struct fixed_new_option_reply_meta_context { +struct nbd_fixed_new_option_reply_meta_context { uint32_t context_id; /* metadata context ID */ /* followed by a string */ } __attribute__((packed)); /* NBD_REPLY_TYPE_BLOCK_STATUS block descriptor. */ -struct block_descriptor { +struct nbd_block_descriptor { uint32_t length; /* length of block */ uint32_t status_flags; /* block type (hole etc) */ } __attribute__((packed)); @@ -144,14 +157,14 @@ struct block_descriptor { /* New-style handshake server reply when using NBD_OPT_EXPORT_NAME. * Modern clients use NBD_OPT_GO instead of this. */ -struct new_handshake_finish { +struct nbd_new_handshake_finish { uint64_t exportsize; uint16_t eflags; /* per-export flags */ char zeroes[124]; /* must be sent as zero bytes */ } __attribute__((packed)); /* Request (client -> server). */ -struct request { +struct nbd_request { uint32_t magic; /* NBD_REQUEST_MAGIC. */ uint16_t flags; /* Request flags. */ uint16_t type; /* Request type. */ @@ -161,14 +174,14 @@ struct request { } __attribute__((packed)); /* Simple reply (server -> client). */ -struct simple_reply { +struct nbd_simple_reply { uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC. */ uint32_t error; /* NBD_SUCCESS or one of NBD_E*. */ uint64_t handle; /* Opaque handle. */ } __attribute__((packed)); /* Structured reply (server -> client). */ -struct structured_reply { +struct nbd_structured_reply { uint32_t magic; /* NBD_STRUCTURED_REPLY_MAGIC. */ uint16_t flags; /* NBD_REPLY_FLAG_* */ uint16_t type; /* NBD_REPLY_TYPE_* */ @@ -176,15 +189,20 @@ struct structured_reply { uint32_t length; /* Length of payload which follows. */ } __attribute__((packed)); -struct structured_reply_offset_data { +struct nbd_structured_reply_offset_data { uint64_t offset; /* offset */ /* Followed by data. */ } __attribute__((packed)); -struct structured_reply_error { +struct nbd_structured_reply_offset_hole { + uint64_t offset; + uint32_t length; /* Length of hole. */ +} __attribute__((packed)); + +struct nbd_structured_reply_error { uint32_t error; /* NBD_E* error number */ uint16_t len; /* Length of human readable error. */ - /* Followed by human readable error string. */ + /* Followed by human readable error string, and possibly more structure. */ } __attribute__((packed)); #define NBD_REQUEST_MAGIC 0x25609513 @@ -221,9 +239,7 @@ struct structured_reply_error { #define NBD_CMD_FLAG_REQ_ONE (1<<3) #define NBD_CMD_FLAG_FAST_ZERO (1<<4) -/* Error codes (previously errno). - * See http://git.qemu.org/?p=qemu.git;a=commitdiff;h=ca4414804114fd0095b317785b... - */ +/* NBD error codes. */ #define NBD_SUCCESS 0 #define NBD_EPERM 1 #define NBD_EIO 5 diff --git a/server/protocol-handshake-newstyle.c b/server/protocol-handshake-newstyle.c index 104796a..413dcf0 100644 --- a/server/protocol-handshake-newstyle.c +++ b/server/protocol-handshake-newstyle.c @@ -55,7 +55,7 @@ static int send_newstyle_option_reply (struct connection *conn, uint32_t option, uint32_t reply) { - struct fixed_new_option_reply fixed_new_option_reply; + struct nbd_fixed_new_option_reply fixed_new_option_reply; fixed_new_option_reply.magic = htobe64 (NBD_REP_MAGIC); fixed_new_option_reply.option = htobe32 (option); @@ -83,7 +83,7 @@ static int send_newstyle_option_reply_exportname (struct connection *conn, uint32_t option, uint32_t reply) { - struct fixed_new_option_reply fixed_new_option_reply; + struct nbd_fixed_new_option_reply fixed_new_option_reply; size_t name_len = strlen (exportname); uint32_t len; @@ -119,8 +119,8 @@ send_newstyle_option_reply_info_export (struct connection *conn, uint32_t option, uint32_t reply, uint16_t info, uint64_t exportsize) { - struct fixed_new_option_reply fixed_new_option_reply; - struct fixed_new_option_reply_info_export export; + struct nbd_fixed_new_option_reply fixed_new_option_reply; + struct nbd_fixed_new_option_reply_info_export export; fixed_new_option_reply.magic = htobe64 (NBD_REP_MAGIC); fixed_new_option_reply.option = htobe32 (option); @@ -147,8 +147,8 @@ send_newstyle_option_reply_meta_context (struct connection *conn, uint32_t context_id, const char *name) { - struct fixed_new_option_reply fixed_new_option_reply; - struct fixed_new_option_reply_meta_context context; + struct nbd_fixed_new_option_reply fixed_new_option_reply; + struct nbd_fixed_new_option_reply_meta_context context; const size_t namelen = strlen (name); debug ("newstyle negotiation: %s: replying with %s id %d", @@ -213,13 +213,13 @@ finish_newstyle_options (struct connection *conn, uint64_t *exportsize) static int negotiate_handshake_newstyle_options (struct connection *conn) { - struct new_option new_option; + struct nbd_new_option new_option; size_t nr_options; uint64_t version; uint32_t option; uint32_t optlen; char data[MAX_OPTION_LENGTH+1]; - struct new_handshake_finish handshake_finish; + struct nbd_new_handshake_finish handshake_finish; const char *optname; uint64_t exportsize; @@ -229,10 +229,10 @@ negotiate_handshake_newstyle_options (struct connection *conn) return -1; version = be64toh (new_option.version); - if (version != NEW_VERSION) { + if (version != NBD_NEW_VERSION) { nbdkit_error ("unknown option version %" PRIx64 ", expecting %" PRIx64, - version, NEW_VERSION); + version, NBD_NEW_VERSION); return -1; } @@ -296,7 +296,7 @@ negotiate_handshake_newstyle_options (struct connection *conn) if (conn->send (conn, &handshake_finish, (conn->cflags & NBD_FLAG_NO_ZEROES) - ? offsetof (struct new_handshake_finish, zeroes) + ? offsetof (struct nbd_new_handshake_finish, zeroes) : sizeof handshake_finish, 0) == -1) { nbdkit_error ("write: %s: %m", optname); return -1; @@ -670,7 +670,7 @@ negotiate_handshake_newstyle_options (struct connection *conn) int protocol_handshake_newstyle (struct connection *conn) { - struct new_handshake handshake; + struct nbd_new_handshake handshake; uint16_t gflags; gflags = (NBD_FLAG_FIXED_NEWSTYLE | NBD_FLAG_NO_ZEROES) & mask_handshake; @@ -678,7 +678,7 @@ protocol_handshake_newstyle (struct connection *conn) debug ("newstyle negotiation: flags: global 0x%x", gflags); memcpy (handshake.nbdmagic, "NBDMAGIC", 8); - handshake.version = htobe64 (NEW_VERSION); + handshake.version = htobe64 (NBD_NEW_VERSION); handshake.gflags = htobe16 (gflags); if (conn->send (conn, &handshake, sizeof handshake, 0) == -1) { diff --git a/server/protocol-handshake-oldstyle.c b/server/protocol-handshake-oldstyle.c index 87cb265..8faa4f0 100644 --- a/server/protocol-handshake-oldstyle.c +++ b/server/protocol-handshake-oldstyle.c @@ -46,7 +46,7 @@ int protocol_handshake_oldstyle (struct connection *conn) { - struct old_handshake handshake; + struct nbd_old_handshake handshake; uint64_t exportsize; uint16_t gflags, eflags; @@ -61,7 +61,7 @@ protocol_handshake_oldstyle (struct connection *conn) memset (&handshake, 0, sizeof handshake); memcpy (handshake.nbdmagic, "NBDMAGIC", 8); - handshake.version = htobe64 (OLD_VERSION); + handshake.version = htobe64 (NBD_OLD_VERSION); handshake.exportsize = htobe64 (exportsize); handshake.gflags = htobe16 (gflags); handshake.eflags = htobe16 (eflags); diff --git a/server/protocol.c b/server/protocol.c index 8df5ed5..89fbdfa 100644 --- a/server/protocol.c +++ b/server/protocol.c @@ -367,7 +367,7 @@ send_simple_reply (struct connection *conn, uint32_t error) { ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&conn->write_lock); - struct simple_reply reply; + struct nbd_simple_reply reply; int r; int f = (cmd == NBD_CMD_READ && !error) ? SEND_MORE : 0; @@ -404,8 +404,8 @@ send_structured_reply_read (struct connection *conn, * that yet we acquire the lock for the whole function. */ ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&conn->write_lock); - struct structured_reply reply; - struct structured_reply_offset_data offset_data; + struct nbd_structured_reply reply; + struct nbd_structured_reply_offset_data offset_data; int r; assert (cmd == NBD_CMD_READ); @@ -442,7 +442,7 @@ send_structured_reply_read (struct connection *conn, /* Convert a list of extents into NBD_REPLY_TYPE_BLOCK_STATUS blocks. * The rules here are very complicated. Read the spec carefully! */ -static struct block_descriptor * +static struct nbd_block_descriptor * extents_to_block_descriptors (struct nbdkit_extents *extents, uint16_t flags, uint32_t count, uint64_t offset, @@ -451,13 +451,14 @@ extents_to_block_descriptors (struct nbdkit_extents *extents, const bool req_one = flags & NBD_CMD_FLAG_REQ_ONE; const size_t nr_extents = nbdkit_extents_count (extents); size_t i; - struct block_descriptor *blocks; + struct nbd_block_descriptor *blocks; /* This is checked in server/plugins.c. */ assert (nr_extents >= 1); /* We may send fewer than nr_extents blocks, but never more. */ - blocks = calloc (req_one ? 1 : nr_extents, sizeof (struct block_descriptor)); + blocks = calloc (req_one ? 1 : nr_extents, + sizeof (struct nbd_block_descriptor)); if (blocks == NULL) { nbdkit_error ("calloc: %m"); return NULL; @@ -528,8 +529,8 @@ send_structured_reply_block_status (struct connection *conn, struct nbdkit_extents *extents) { ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&conn->write_lock); - struct structured_reply reply; - CLEANUP_FREE struct block_descriptor *blocks = NULL; + struct nbd_structured_reply reply; + CLEANUP_FREE struct nbd_block_descriptor *blocks = NULL; size_t nr_blocks; uint32_t context_id; size_t i; @@ -548,7 +549,7 @@ send_structured_reply_block_status (struct connection *conn, reply.flags = htobe16 (NBD_REPLY_FLAG_DONE); reply.type = htobe16 (NBD_REPLY_TYPE_BLOCK_STATUS); reply.length = htobe32 (sizeof context_id + - nr_blocks * sizeof (struct block_descriptor)); + nr_blocks * sizeof (struct nbd_block_descriptor)); r = conn->send (conn, &reply, sizeof reply, SEND_MORE); if (r == -1) { @@ -583,8 +584,8 @@ send_structured_reply_error (struct connection *conn, uint32_t error) { ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&conn->write_lock); - struct structured_reply reply; - struct structured_reply_error error_data; + struct nbd_structured_reply reply; + struct nbd_structured_reply_error error_data; int r; reply.magic = htobe32 (NBD_STRUCTURED_REPLY_MAGIC); @@ -616,7 +617,7 @@ int protocol_recv_request_send_reply (struct connection *conn) { int r; - struct request request; + struct nbd_request request; uint16_t cmd, flags; uint32_t magic, count, error = 0; uint64_t offset; diff --git a/tests/test-layers.c b/tests/test-layers.c index 1097f15..e82cbea 100644 --- a/tests/test-layers.c +++ b/tests/test-layers.c @@ -86,13 +86,13 @@ main (int argc, char *argv[]) int err; pthread_t thread; int sock; - struct new_handshake handshake; + struct nbd_new_handshake handshake; uint32_t cflags; - struct new_option option; - struct new_handshake_finish handshake_finish; + struct nbd_new_option option; + struct nbd_new_handshake_finish handshake_finish; uint16_t eflags; - struct request request; - struct simple_reply reply; + struct nbd_request request; + struct nbd_simple_reply reply; char data[512]; #ifndef HAVE_EXIT_WITH_PARENT @@ -175,7 +175,7 @@ main (int argc, char *argv[]) exit (EXIT_FAILURE); } if (memcmp (handshake.nbdmagic, "NBDMAGIC", 8) != 0 || - be64toh (handshake.version) != NEW_VERSION) { + be64toh (handshake.version) != NBD_NEW_VERSION) { fprintf (stderr, "%s: unexpected NBDMAGIC or version\n", program_name); exit (EXIT_FAILURE); @@ -189,7 +189,7 @@ main (int argc, char *argv[]) } /* Send NBD_OPT_EXPORT_NAME with no export name. */ - option.version = htobe64 (NEW_VERSION); + option.version = htobe64 (NBD_NEW_VERSION); option.option = htobe32 (NBD_OPT_EXPORT_NAME); option.optlen = htobe32 (0); if (send (sock, &option, sizeof option, 0) != sizeof option) { -- 2.23.0

Some further small changes are made to allow this header to be used from arbitrary ISO C compilers. It can now be used from other projects. --- common/protocol/Makefile.am | 2 ++ common/protocol/nbd-protocol.h | 38 ++++++++++++++++++++-------------- 2 files changed, 24 insertions(+), 16 deletions(-) diff --git a/common/protocol/Makefile.am b/common/protocol/Makefile.am index 74c288a..b115c58 100644 --- a/common/protocol/Makefile.am +++ b/common/protocol/Makefile.am @@ -37,6 +37,8 @@ EXTRA_DIST = \ generate-protostrings.sh \ $(NULL) +include_HEADERS = nbd-protocol.h + noinst_LTLIBRARIES = libprotocol.la libprotocol_la_SOURCES = \ diff --git a/common/protocol/nbd-protocol.h b/common/protocol/nbd-protocol.h index 724ffb6..7df411a 100644 --- a/common/protocol/nbd-protocol.h +++ b/common/protocol/nbd-protocol.h @@ -36,10 +36,16 @@ #include <stdint.h> /* Note that all NBD fields are sent on the wire in network byte - * order, so we must use beXXtoh or htobeXX when reading or writing + * order, so you must use beXXtoh or htobeXX when reading or writing * these structures. */ +#if defined(__GNUC__) || defined(__clang__) +#define NBD_ATTRIBUTE_PACKED __attribute__((__packed__)) +#else +#define NBD_ATTRIBUTE_PACKED +#endif + #define NBD_MAX_STRING 4096 /* Maximum length of a string field */ /* Old-style handshake. */ @@ -50,7 +56,7 @@ struct nbd_old_handshake { uint16_t gflags; /* global flags */ uint16_t eflags; /* per-export flags */ char zeroes[124]; /* must be sent as zero bytes */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; #define NBD_OLD_VERSION UINT64_C(0x420281861253) @@ -59,7 +65,7 @@ struct nbd_new_handshake { char nbdmagic[8]; /* "NBDMAGIC" */ uint64_t version; /* NBD_NEW_VERSION */ uint16_t gflags; /* global flags */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; #define NBD_NEW_VERSION UINT64_C(0x49484156454F5054) @@ -69,14 +75,14 @@ struct nbd_new_option { uint32_t option; /* NBD_OPT_* */ uint32_t optlen; /* option data length */ /* option data follows */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* Newstyle handshake OPT_EXPORT_NAME reply message. */ struct nbd_export_name_option_reply { uint64_t exportsize; /* size of export */ uint16_t eflags; /* per-export flags */ char zeroes[124]; /* optional zeroes */ -} __attribute__((packed));; +} NBD_ATTRIBUTE_PACKED;; /* Fixed newstyle handshake reply message. */ struct nbd_fixed_new_option_reply { @@ -84,7 +90,7 @@ struct nbd_fixed_new_option_reply { uint32_t option; /* option we are replying to */ uint32_t reply; /* NBD_REP_* */ uint32_t replylen; -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; #define NBD_REP_MAGIC UINT64_C(0x3e889045565a9) @@ -140,19 +146,19 @@ struct nbd_fixed_new_option_reply_info_export { uint16_t info; /* NBD_INFO_EXPORT */ uint64_t exportsize; /* size of export */ uint16_t eflags; /* per-export flags */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* NBD_REP_META_CONTEXT reply (follows fixed_new_option_reply). */ struct nbd_fixed_new_option_reply_meta_context { uint32_t context_id; /* metadata context ID */ /* followed by a string */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* NBD_REPLY_TYPE_BLOCK_STATUS block descriptor. */ struct nbd_block_descriptor { uint32_t length; /* length of block */ uint32_t status_flags; /* block type (hole etc) */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* New-style handshake server reply when using NBD_OPT_EXPORT_NAME. * Modern clients use NBD_OPT_GO instead of this. @@ -161,7 +167,7 @@ struct nbd_new_handshake_finish { uint64_t exportsize; uint16_t eflags; /* per-export flags */ char zeroes[124]; /* must be sent as zero bytes */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* Request (client -> server). */ struct nbd_request { @@ -171,14 +177,14 @@ struct nbd_request { uint64_t handle; /* Opaque handle. */ uint64_t offset; /* Request offset. */ uint32_t count; /* Request length. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* Simple reply (server -> client). */ struct nbd_simple_reply { uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC. */ uint32_t error; /* NBD_SUCCESS or one of NBD_E*. */ uint64_t handle; /* Opaque handle. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* Structured reply (server -> client). */ struct nbd_structured_reply { @@ -187,23 +193,23 @@ struct nbd_structured_reply { uint16_t type; /* NBD_REPLY_TYPE_* */ uint64_t handle; /* Opaque handle. */ uint32_t length; /* Length of payload which follows. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; struct nbd_structured_reply_offset_data { uint64_t offset; /* offset */ /* Followed by data. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; struct nbd_structured_reply_offset_hole { uint64_t offset; uint32_t length; /* Length of hole. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; struct nbd_structured_reply_error { uint32_t error; /* NBD_E* error number */ uint16_t len; /* Length of human readable error. */ /* Followed by human readable error string, and possibly more structure. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; #define NBD_REQUEST_MAGIC 0x25609513 #define NBD_SIMPLE_REPLY_MAGIC 0x67446698 -- 2.23.0

On 9/24/19 4:07 PM, Richard W.M. Jones wrote: Actually, I just realized that this fallback is wrong - it induces padding bytes, and thus creates a struct incompatible with the wire format. We're better off making the #else use #error Please port to your compiler's notion of a packed struct so that the file serves as a reference, but does not get mistakenly used with incorrect padding. This one actually gets wire alignment without packing. This one would get tail padding, messing up anyone using sizeof(struct nbd_new_handshake). ... > @@ -140,19 +146,19 @@ struct nbd_fixed_new_option_reply_info_export { > uint16_t info; /* NBD_INFO_EXPORT */ > uint64_t exportsize; /* size of export */ > uint16_t eflags; /* per-export flags */ > -} __attribute__((packed)); > +} NBD_ATTRIBUTE_PACKED; and here's one that gets member offsets wrong, if packed is not used. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org